\begin{table}[htpb]
\begin{center}
\begin{threeparttable}
\begin{tabular}{l d{2} d{2} d{3}}
\toprule
\midrule
Variable & \multicolumn{1}{r}{0} & \multicolumn{1}{r}{1} & \multicolumn{1}{r}{Diff} \\
\midrule
(mean) w_int_mins &     2.19&     9.46&    7.269\textsuperscript{***} \\
&(0.60)&(0.10)&(0.640) \\
(mean) nw_int_mins &     0.69&     1.13&    0.437\textsuperscript{} \\
&(0.19)&(0.23)&(0.301) \\
(mean) Avgnoisedb &    78.90&    76.78&   -2.122\textsuperscript{} \\
&(1.33)&(1.59)&(2.059) \\
(mean) Roomtemperaturec &    28.49&    30.82&    2.334\textsuperscript{*} \\
&(0.96)&(0.77)&(1.241) \\
N & \multicolumn{1}{r}{23} & \multicolumn{1}{r}{21} & \multicolumn{1}{r}{44} \\ 
\midrule
\bottomrule
\end{tabular}
\begin{tablenotes}
\item [1] Significance levels:$ \quad ^{*}<10\% \quad ^{**}<5\% \quad ^{***}<1\%$ 
\item [2] Standard errors in parentheses
\end{tablenotes}
\end{threeparttable}
\end{center}
\end{table}
